 Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum            Session 1, Part B:
Which Rock Is the Largest?

In This Part: Measuring Surface Area | Measuring Volume | Measuring Weight

Some people might suggest that we examine the weight of rocks to determine which is the biggest. To measure the weight of your rock, you will need a two-pan balance and a three-arm balance. Note 7

 Two-Pan Balance Three-Arm Balance   Estimate the weight of your rock. (Later, you can compare your estimate with the approximate weight you've measured.)  Problem B7 What information can you gather by using a two-pan balance? Can you determine the weight of your rock with this balance? Note 8

If you have access to a two-pan balance, use it to determine the weight of your rock. Problem B8 How does a three-arm balance scale work? Can you determine the weight of your rock with this balance? If you have access to a three-arm balance, use it to determine the weight of your rock. Problem B9 In science, a distinction is made between mass and weight. What do you know about these two terms? Problem B10 How precise are your rock's measurements? What might affect the precision of this measurement? Problem B11 Now that you've experimented with several different types of measures, which would you use to determine the largest rock in a group of rocks? Should you use a combination of measures? Note 9      Problem B12 There are very interesting relationships among metric measures involving water. One cubic centimeter of water is equivalent to 1 mL of water. In addition, 1 mL of water (or 1 cm3 of water) weighs 1 g. You may then conclude that the amount of water your rock displaced should be equivalent to the weight of your rock. What is faulty about this line of reasoning?  Is the rock heavier, lighter, or the same weight as water?   Close Tip   Problem B13 Are there any other measurements you could use to determine the largest rock in a group of rocks?   Session 1: Index | Notes | Solutions | Video